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Oishigawa Pyroclastic Flow Kitayatsugatake Subgroup, 1988

Abbr.: OP

• Type locality: 990 m above sea level of Oishi river, Sakuho city, Minamisaku county, Nagano prefecture
• Volcanic rocks
• early Pleistocene (1.02 Ma, K-Ar)

• Lithofacies: Orthopyroxene clinopyroxene hornblende dacite
• Lithofacies: Pyroclastic flow (Block-and-ash flow)

• Eruptive volume: 0.1 km³ or more
• Thickness: ca. 10 m
• Upper limit: Mizunashigawa Lavas

------ Conformity, ~~~~~~ Unconformity, ~~~--- Local unconformity, '''/,, Interfingered, :::::: Fault, /--/-- Thrust, +__+__ Ground surface, ?--?-- Unknown

• Distribution: 975 - 1,000 m above sea level, Mizunashi river - Oishi river, Sakuho city, Minamisaku county, Nagano pref.

• Nishiki and Takahashi (2012) Jour. Geol. Soc. Japan, vol.118, no.8, pp.499-515 DOI
• Nishiki et al. (2007) Jour. Geol. Soc. Japan, vol.113, no.5, pp.193-211 DOI